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CNet is reporting that a free Skype client will finally be landing on the iPhone this week. Unfortunately some are saying that it seems many of the "critical" pieces of functionality are still missing. While the Skype engineers claim their native client will offer better audio quality (because there is no need to route through another server and transcode audio) they are still missing text messaging, file transfers, and integrated voice mail. Since the iPhone does not allow for multiple programs running concurrently, many are expecting existing multi-function apps like Fring and NimBuzz to continue their reign at the top.

It's an arbitrary restriction and only applies to third-party apps. The aim is to avoid third-party apps draining the battery by doing a lot of things in the background, or preventing other things from working by using all of the RAM (the iPhone doesn't enable swapping, I believe).

In theory, this is a good idea. Unfortunately, the whole philosophy of the iPhone is that Apple knows better than the owner of the device (which is probably true in the case of a lot of the users...) so there is no way of overriding this.

Skype will only use the WiFi network, not the 'unlimited' ATT data plan so you will only be able to use it while tethered to a local hotspot, not out roaming in the wild. ATT and Apple protect their revenue and force you to use your paid minutes instead of the 'unlimited' data plan that you are paying big bucks for...

iPhones can run multiple apps, but the public SDK does not allow developers to write apps that run in the background. Apple can certainly write apps that run in the background, though. The music service, for one. The phone service, etc. Additionally, developers for jailbroken phones can run applications in the background because they're not constrained by the official SDK.

It'll work abroad via WiFi for calling the US for sure. I did it with my Curve 8320, calling the US from an Apple store in Nagoya, Japan. Didn't try to get anyone to call ME from the US. But the phone behaves like you're IN the US. So, I couldn't make calls TO Japan (I had a crappy plan).

It's not that it can't be done, it's that it sucks battery life. Did you view the presentation from the iPhone 3.0 event? They ran tests on running background apps on multiple platforms and measured battery life, it it shortened it by 80%. Considering how much MORE iPhone users seem to use their phones this could be a major problem and why they chose not to enable background apps.

I'm not certain that Skype would work on a 3G network. It's not the bandwidth, but the latency. All mobile data networks I've used (GPRS, EDGE and 3G) have had *terrible* latency, and not only terrible latency but very unpredictable latency. If you use SSH over 3G, you'll find you type a bunch of stuff and perhaps 15 seconds later, what you typed will echo back. Other times, 3G latency is somewhat better, it only feels like doing ssh to a machine with a high load average on the other side of the planet. But the typical latency of the mobile data networks varies from poorer than 56k dialup at best to terrible at worst.

I'm not sure it's the background apps that are the problem so much as what 99% of background apps do while in the background. The main reason to run an application in the background is to do networking, and that means the radio has to move from GPRS mode into EDGE or 3G mode, which drains significantly more power. It's not at all surprising that it causes a much higher battery drain if background apps keep waking the cellular hardware while it should be idle.

As soon as you bring up the cellular network to get data, you're spending several seconds negotiating with the tower to switch from GPRS mode to EDGE or 3G and obtain an IP number for the interface. Then, your initial DNS lookup, at least based on my experience with AT&T's EDGE network can potentially add another 10-15 seconds in the worst case. Pull even a trivial amount of data and you've probably added another ten or fifteen seconds. At that point, you've spent the better part of a minute with the radio draining significantly more power than it does in its normal GPRS/waiting-for-calls standby state. Do this once a minute, and you almost might as well be talking on the phone to somebody. Okay, so maybe that's a bit of an exaggeration, but it does drain a lot more power....

Having read the iPhone Memory Management guide a number of times, I can assure you that that the iPhone's virtual memory model does not include disk swapping. The Apple documentation says exactly this.